A flywheel in the form of a uniformly thick disk of radius 1.33 m, has a mass of 40.6 kg and spins counterclockwise at 147 rpm. Calculate the constant torque required to stop it in 3.25 min.
You can use this relationship: T = a*I where a is the angular acceleration, I is the moment of inertia and T is the torque.
In your question the initial angular velocity is 2*pi*147/60 rad/s and a = 2*pi*147/(60*3.25*60) = 78.9*10^-3rad/s^2
For a uniform disc of mass m and radius r rotating about an axis passing through the centre and normal to the plane of the disc, I = 0.5*m*r^2
T = a*I = 78.9*10^-3*0.5*40.6*1.33^2 = 2.83Nm